1. Field of the Invention
The present invention relates to a vibrator.
2. Description of the Related Art
A vibrator, a device converting electrical energy into mechanical vibrations using the principle of the generation of electromagnetic force, is mounted in a mobile phone, or the like, to be used for silently notifying a user of call reception. In addition, as the market for mobile devices such as mobile phones, and the like, has rapidly expanded and various additional functions have been added to mobile devices, a mobile device having a small size and high quality has been required. In this situation, the need for developing a vibrator having novel structure capable of overcoming disadvantages of existing products and significantly improved quality has increased.
Further, as the release onto the market of smartphones, among other mobile phones, has rapidly increased, a touchscreen scheme has been adopted for use therewith, such that the adoption of vibration motors has increased in order to generate vibrations to provide feedback when a user touches a smartphone. Vibrational performance required when a touchscreen is touched is as follows. First, as the amount of vibrations generation at the time of the touch is increased to be greater than that of vibrations generated at the time of call reception, an operation lifespan is required to be increased. Second, in order to increase user satisfaction when a user is provided with vibrations at the time of a touch, a vibration response speed needs to be increased in accordance with a touch speed of the screen.
As a product capable of implementing the characteristics as described above, there is provided a piezo haptic actuator. Such a piezo haptic actuator uses the principle of a converse piezoelectric effect, which generates displacement of a piezo element when a voltage is applied thereto, and vibratory force is generated by allowing a mass body provided on a moving element to move by the generated displacement.
A vibrator having such a structure may be characterized in that a frequency band width allowing for vibration force to be obtained at a predetermined level or more is wider, such that stable vibrational characteristics may be implemented, and vibrations having a high or a low frequency, rather than a single frequency, may be variously used within a predetermined frequency range. In addition, since rapid operational response characteristics may be implemented, the vibrator as described above may be suitable for implementing haptic vibrations in mobile devices such as mobile phones, and the like.
Meanwhile, the piezo element generating the vibration as described above may be mounted on an elastic member to vibrate, but there may be a problem in that the elastic member may be damaged by inertial force of amass body mounted on the elastic member when external impacts are applied thereto (particularly, in an axial direction).